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TM 07661B-14/1
APPENDIX A
of both shutoff valve and tip are now accessible for cleaning.
CAUTION
Use of metal tools, such as screwdrivers, awls, etc., is discouraged; any scraped or gouged
areas in the dry chemical passageway will compound clogging problems, and may cause
leaks.
(5)
Clean accumulations of dry chemical powder from inside the tip and shutoff valve with a soft wood or hard
rubber scraper.
WARNING
Use normal precautions when cleaning with compressed air to prevent injury to personnel.
Compressed air for cleaning purposes will not exceed 30 psi. User should wear safety
goggles, and should not direct the stream of air toward himself or other persons.
(6)
After nozzle is completely cleaned, use clean dry compressed air or nitrogen to remove all traces of dry
chemical powder or foreign matter.
(7)
Reassembly of the dry chemical nozzle is accomplished in reverse order of disassembly, as follows:
(a)
Thread the tip (5) onto shutoff valve body (7), tighten securely.
(b)
Attach the nozzle to the tie bar with two screws (2).
(c)
Install quick-disconnect fitting (1).
(d)
Connect the nozzle to the dry chemical discharge hose.
b.
Cleaning AFFF Discharge Nozzle. Remove the AFFF nozzle from the tie bar and disconnect it from the
discharge hose per steps (1) and (2) of preceding paragraph a.
(1)
Turn nozzle tip (4, figure 3-12) counterclockwise to remove it from the shutoff valve (6).
(2)
Soak both the tip and nozzle for a minimum of 30 minutes in a warm water and soap solution.
(3)
Flush both shutoff valve and tip under a strong stream of water. Open valve fully to allow flow of water.
Repeat with handle in various intermediate positions.
(4)
Repeat step (3) while backflushing.
(5)
Reassemble the nozzle and attach it to the AFFF discharge hose.
c.
Clearing Dry Chemical Discharge Hose. The dry chemical discharge hose can be cleared of caked dry chemical
powder by taking the action described in steps (1) through (7).
CAUTION
End of hose must be secured during hose-cleaning operations to prevent lashing action of hose
when powder and gases are discharged.
(1)
Unwind handline to its maximum length.
(2)
Remove hose from discharge nozzle by uncoupling quick disconnect fitting.
(3)
Put discharge end of hose in suitable large container to avoid contaminating area.
A 3-36
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